Railway car roof



May 13, 1941. J. M. RUDEL RAIPWAY CAR ROOF Filed July 25, 1939 2 Sheets-Sheet l K Fi'e..5.

N VEN To R 8 JOHN Mam/1.1. RUDEL Q" y 1941- J. M. RUDEL 2,241,738

RAILWAY, 01m ROOF Filed July 25,1939 7 2 Sheets-Sheet 2 IN VEN 7" o R Jo HIV Mam/1. L Rana-L Patented May 13, 1941 UNITED ST- TES PATENT OFFICE Application July 25, 1939, Serial No. 286,476 In Canada March 10-, 1939 Claims.

This invention relates to metal car roofs.

Introduction In the construction of a car roof, the principal objectives are to provide a structure which is light, fiexible to a suitable degree and in the right directions, has adequate load bearing capacity, and is sufficiently strong to withstand extreme stresses exerted by the car movements. In the accomplishment of these objectives, many different types of structure have been developed.

To give-the roof sheets adequate load bearing capacity, these structures have employed stiffening ribs, bulges, or other protuberances of various shapes. To further this capacity, special joints between the sheets have been used, which are designed to take up the stresses to which the sheets themselves are subjected.

It is now realized that these structures have often sacrificed flexibility to attain greater load bearing capacity and have thus partially defeated their own ends because flexibility is an essential element in attaining durability. In many of these structures, the practice has been to fabricate the sheets in such a way that sharp angles occur between portions of the sheets causing weakened areas subject to fatigue, buckling, and eventual rupture under the stresses and strains to which they are subjected in strenuous use on a freight car.

I Objects Having regard to the foregoing, it is a principal object of the present invention to provide an improved car roof structure giving adequate load bearing capacity besides aifording the required flexibility and ability to relieve the strains set up by torsional stresses.

It is a further object of the invention to provide a roof of this nature in which the elements are relatively simple and easy to fabricate.

It is a still further object of the invention to provide a roof sheet in which extreme deformation of the metal is avoided.

Structure marginal edges of the sheet, the stiffening members cooperating with the sheet to provide a suitable thickness of metal to permit of the joint being completed by welding. This structure is particularly applicable to roofs of the radial type in which the sheets are arched transversely to the car, the transverse arch combining with the arch of the bulge to increase the torsionability of the sheets.

The drawings Having thus generally described the nature of the invention, reference will be made to the accompanying drawings illustrating a preferred embodiment, and in which:

Figure 1 is a plan view of a car roof constructed according to this preferred embodiment of the invention and. illustrating particularly one form of the improved roof sheet and seam joint.

Figure 2 is an enlarged partial cross section along the line 2-2 of Figure 1.

Figure 3 is an enlarged cross section along the line 3-3 of Figure 1.

Figure 4 is an enlarged cross section along the line 44 .of Figure 1.

Figure 5 is a greatl enlarged cross section through a seam joint of the roof shown in Figures v1 to 4 as for instance atthe line 4-4.

Figure 6 is a greatly enlarged end elevation of a seam joint of the roof shown in Figures 1 to 4.

Figure '7 is a fragmentary vertical cross section, on a scale approximately double that of Figures 2-4, through a roof embodying an alternative form of seam joint.

Figure 8 is an enlargedfragmentary cross section, on the scale of Figures 5 and 6, through a seam joint of the type shown in Figure 7.

Figures 9 and 10 are fragmentary vertical transverse cross sections, on the scale of Figure 1, through a roof embodying an alternative form of roof sheet.

Detailed description Referring more particularly to the drawings, A represents a car roof of the radially arched type, constructed of a series of metal roof sheets [0, of the special form referredto above. The roof sheets are interconnected at their marginal edges by welded seam joints H and attached to the car by conventional means, as for instance, by integral eaves flanges 12 secured to the side plates 13 of the car.

The sheets are specially formed with a bulge 20 of constant width, taking in the major portion of the width of the sheet, and whose cross section is a shallow are increasing in height and in curvature from adjacent the eaves flanges to adjacent the centre line of the roof, substantially as indicated in the figures. Adjacent to the sides of the sheet this bulge merges into a portion curved in cross section oppositely to the bulge, to form upturned marginal flanges 2! adapted to lie adjacent to and to be joined to the next roof sheet. More specifically, this bulge may be described as having a convex portion.

Unlike most prior art structures, the sheets are no where bent to an angle or a curve sufliciently acute to distort the metal to a degree at which it might fatigue and eventually rupture. Surprisingly, however, despite the teachings of the prior art that most extreme protuberances of the sheet are necessary for making the roof selfsupporting, the present simple structure fulfills its purpose admirably by giving the roof remarkable strength and at the same time the necesary flexibility required to achieve durability. In addition, the less pronounced bulge of the roof sheet is easier to fabricate than some of the more extreme forms of protuberances.

In the form illustrated in Figures 1 to 4 the joint between the flanges 2| of adjacent sheets is formed with stiffening members 22 overlapping the edges of the roof sheets and conforming to their shape. The top edges of the flanges and of the stiffening members lie substantially of even height and are welded together as at 23. The stiffening members 22 are also seam-welded to the roof sheets as at 24. In this manner a strong joint is formed in which the elements are all securely connected by at least two welds. Alternatively, a single stifiening member, such as a seam cap having outwardly extending flanges, may be used, in which case the flanges and seam cap are spot welded or riveted together. However, the use of two stifiening members is preferred, as permitting access in welding together the edges of the sheets.

A roof lining 2B is connected to the side plates [3 of the car and also centrally to the roof through a filler strip 27, the latter being held to the roof by a U-member 28. The U-member includes outwardly extending flanges 29 connected to the roof adjacent the joints as for instance by rivets extending through the edges of the sheets, the flanges, and the stiffening members 22. The body of each U-member is bolted to the filler strip 21.

Alternative forms An alternative form of roof is illustrated in Figures '7 and 8 in which the margins of the roof sheets, instead of being curved upwards to form flanges, are carried straight out to the edges. In this case, flat stiffening plates 3| are seam welded as at 32 to the marginal portions and, in assembly, the edges, including the stiffening members, are butted together and joined by a weld as at 33. The stifiening members are preferably formed with a slight bevel on their adjacent edges to permit greater fusion of the four joint sections, allowing the formation of a stronger joint. The flat stifiening plates 3| are also readily folded over the eaves when the roof and the side plates of the car are connected.

Another alternative form of roof sheet is illustrated in Figures 9 and 10 in which the sheet is provided with twin spaced apart bulges 40 instead of the single bulge as in the previous figures.

In all forms of roof, the joints are so constructed that the sheets merge evenly into structural elements to which they are joined besides being joined to each other.

Function By reason of the gradual curvature of the stiffening bulge and, as will be seen, by the nature of the joints, the horizontal stresses communicated to the sheets by the movements of. the car are distributed, more or less evenly, throughout the roof. The sheets are capable of expansion and contraction in a vertical direction to compensate for horizontal expansion or contraction when the car is subjected to longitudinal stresses from car movements, changes of temperature or otherwise. There are no extremely bent portions in the metal to cause a concentration of stresses which might eventually result in the weakening and perhaps even the rupture of those portions. Since there are no parts of the roof so rigid as to prevent horizontal or torsional flexure, there is less likelihood of strain on the car body when going around curves.

The remarks of the previous paragraph are especially true when the present design is applied to a radial roof, since the radial curve across the roof is combined with the transversely extending curve of the bulge to give the roof torsionability, that is to say, the capacity to twist and flex suitably to allow for jump of the roof, breathing of the car, or other stresses inflicted upon the roof from sudden stops, shunts, or starting jolts.

Additionally, the sheets are easy to make and to assemble, while the joints are most easily effected by simple operations requiring only conventional equipment.

It will of course be understood that various modifications and applications according to the invention may be made without departing from the spirit thereof or the scope of the claims, so that the exact forms shown are to be taken as illustrative only and not in a limiting sense; it is desired that only such limitations shall be placed thereon as are disclosed in the prior art or are set forth in the accompanying claims.

The sub-titles used throughout the specification are merely to simplify reference thereto and should otherwise be disregarded.

I claim:

1. A car roof sheet of the radially arched type said sheet having side marginal portions adapted to be rigidly connected to an adjacent sheet to form a rigid joint, and downwardly extending eaves portions adapted to be connected rigidly to the car body, said sheet including a longitudinally extending stifiening bulge having a central convex portion of shallow arcuate cross section embracing a major portion of the width of the sheet, concave flanking portions connecting said convex portion to said side marginal portions, said convex and concave portions having arcs of curvature substantially equal and tangential to one another to provide throughout the sheet uniform flexibility and strength, said bulge increasing gradually and uniformly in height from adjacent the eaves portions to the middle portion, said sheet being characterized by the gradual change between contours and complete absence of abrupt bends.

2. A car roof, comprising, roof sheets having their side margins rigidly secured together, each sheet including a longitudinally extending stiffening bulge mainly of shallow arcuate cross section, said bulge increasing in height from the eaves portions of the sheet to the middle portion,

and embracing the major portion of the width of the sheets, the bulge merging gradually into the side marginal portions of the sheets, a reinforcing member overlying each marginal portion and terminating coextensively therewith, the adjacent marginal portions and reinforcing members of respective sheets being Welded together to form a joint, and the side marginal portions being curved on arcs substantially equal and tangential to the arc of curvature of said bulge.

3. A car roof sheet of the radially arched type, said sheet having fiat side marginal portions adapted to be butted end to end against and welded to an adjacent sheet to form a rigid joint and downwardly extending eaves portions adapted to be connected rigidly to the car body, said sheet including a longitudinally extending stiffening bulge having a convex portion of shallow arcuate cross section embracing a major portion of a width of the sheet, concave flanking portions connecting said convex portion and marginal portions, said convex and concave portions having arcs of curvature substantially equal and tangential to one another, to provide throughout the sheet uniform flexibility and strength, said bulge increasing gradually and uniformly in height from adjacent the eaves portions to adjacent the middle portion thereof, said sheet being characterized by the gradual change between contours and complete absence of abrupt bends.

4. A car roof, comprising, roof sheets having their side marginal portions rigidly secured together, each sheet including a longitudinally extending stififening bulge mainly of shallow arouate cross section, said bulge increasing in height from the eaves portions of the sheet to the middle portion and embracing the major portion of the width of the sheet, the bulge merging gradually into arcuate side marginal portions, a reinforcing member overlying each marginal portion, the arcs of curvature of said bulge and marginal portions being substantially equal and tangential to one another, the edges of the adjacent marginal portions of respective sheets being contacted together, the edges of the reinforcing members being spaced apart slightly, a fillet weld joining the edges of the respective reinforcing members and sheets.

5. A car roof, comprising, roof sheets having their side marginal portions rigidly secured together, each sheet including a longitudinally extending stiffening bulge mainly of shallow arcuate cross section, said bulge increasing in height from the eaves portions of the sheet to the middle portion and embracing the major portion of the width of the sheet, the bulge merging gradually into curved side marginal portions, the arcs of curvature of said bulge and marginal portions being substantially equal and tangential to one another, a reinforcing member overlying each marginal portion, the edge portions of the adjacent marginal portions and of the reinforcing members of respective sheets being contacted and welded together to form a joint, a supporting member at each joint between roof sheets, said supporting member including a portion connected to respective sheets and an intermediate portion adapted to support a roof lining member.

JOHN MERRILL RUDEL. 

